Hello! I would do a break down of the subject first to get a better understanding how it's built and based on that come up with a rough plan, like what technique is suitable for what element, what is unique, what repeating, what are the different structures and surfaces. Execution wise, looking at actual game assets helps…
Welcome to Polycount! A good way to learn how to model complex shapes is to give it a try, and post your attempt, like Fabi_G suggested. Then people are more likely to suggest ideas how to improve what you have. For example see How The F*#% Do I Model This? - Reply for help with specific shapes - (Post attempt before…